Evaluation of Finnish comprehensive schools is based on an enhancement-led evaluation model. The model is rooted in historical features of the education and governance systems and a gradual articulation since the 1990s. It builds on the idea that evaluation must benefit, not control, the system being evaluated. The model’s entrenchment has made it possible to oppose the global push for test-based accountability. Finnish education policy supports sample-based testing instead of high-stake standardized testing for whole age cohorts; it is also impossible to form ranking lists that make schools compete through their performance. The chapter concludes that the original programme has successfully endured for decades and has faced little opposition. In addition, the legitimation of a trust-based model is high and can bring political kudos to all the actors involved. Processual shortcomings lacking transparency and discussion make the success only partial. An unresolved contributing feature is the relationship between local and national evaluations. These principles and the process of evaluation have become better articulated through the establishment of the Finnish Education Evaluation Centre, and centralization also brings risks of more radical changes.